In 2006, the United States produced more than 12 billion (12,000,000,000) chicken eggs. In the egg production industry, only the female chicks are productive and the male chicks are currently culled. The culling of male chicks typically occurs after hatching and presents serious problems both economically and ethically. Economically, culling the male chicks is labor intensive and requires that certain waste disposal guidelines be followed. Ethically, the large scale culling of male chicks is undesirable to the industry consumers and the general public.
While there are a number of known methods useful to screen or determine the sex of many avian species, both pre- and post-hatching, the known methods fall short for several reasons. For simplicity, much of the specification will refer to known methods, and the present invention, as they relate to determination of the sex of a chick. However, many of the known methods can be used to determine the sex of other avian species, and the novel system and methods disclosed herein can similarly be utilized for avian species other than chickens. For example, the known pre-hatch screening methods are in some cases unreliable and are only available relatively late in the twenty one (21) day developmental cycle of the chick embryo. Many of the known pre-hatch screening methods analyze chick sex only after day eleven (11) in development which is after the point of development that the chick embryo is considered a sentient animal.
Thus the known pre-hatch screening methods do not avoid the ethical issues associated with post-hatch sexing. Second, many of the current pre-hatch methods are invasive and require sampling the contents of the egg, often by penetrating, or creating a hole in, the egg shell, thus compromising egg quality, embryo survival, physically damaging the egg and potentially introducing a source of contamination. The samples taken from the egg then require cost and time, or intensive assays of DNA, hormones or other metabolites to determine sex.
The known post-hatch sexing methods suffer many of the same drawbacks and limitations as discussed above and require extensive labor and expense or present waste disposal and ethical issues. One wide spread method of determining chick sex after hatching is feather color differentiation, designated on FIG. 1 as “ƒc”. Feathers are elaborate skin appendages that serve many functions on a bird, including communication, regulation of body temperature and in some species, flight. Feathers originate from feather follicles and in the modern chicken, beginning on the 8th day of incubation, feathers have begun to form, and they are readily apparent on the 10th day of incubation. Further, feather color or pigmentation exists by the 10th day of incubation, as shown in FIG. 1. Feather color is determined by the expression of certain pigments by the cells forming the feather/feather precursor. Using feather color differentiation ƒc to sex newly hatched chicks was developed over a century ago, and today, commercial breeds of chickens (as well as some wild type breeds) can be sexed at over 99% accuracy based upon feather color after hatching. One common color scheme used in feather color differentiation ƒc involves breeding chickens with a sex-linked genetic marker so that male chicks are born with brown feathers while female chicks are born with white feathers, or vice versa. As shown in FIG. 1 as an example of developing brown feathers in a female chick embryo, the differentiation of feather color ƒc may exist as early as days 8-10 of egg incubation in some breeds of chickens and persists to hatching.
Accordingly, it is desirable that a method and apparatus be developed that allows for the non-invasive embryonic (or pre-hatch) determination of chick sex using feather color.
The unmet needs described above, as well as others are addressed by various embodiments of the methods, systems, and devices provided by the present application; although it is to be understood that not every embodiment disclosed will address a given need.